info on mercury optimax 135 saltwater.

brembo26

Hi all was just wondering,if some1 can give me any info on the optimax mercury 135 outboard engine. i just serviced one and its fine before the service if you brought it upto top revs an engine management alarm and temp alarm would sound but the minute you drop power they go? After the service theres no more alarms except for when you rev the engine out of gear and the same alarms and symbols appear? i dont have a manual but if anyone has an idea what it could be it would be great. Cheers guys thanks.

Also if anyone has owned or is currently an owner of one have you had any problems faults??

Hifive

brembo26 wrote: »

Hi all was just wondering,if some1 can give me any info on the optimax mercury 135 outboard engine. i just serviced one and its fine before the service if you brought it upto top revs an engine management alarm and temp alarm would sound but the minute you drop power they go? After the service theres no more alarms except for when you rev the engine out of gear and the same alarms and symbols appear? i dont have a manual but if anyone has an idea what it could be it would be great. Cheers guys thanks.

Also if anyone has owned or is currently an owner of one have you had any problems faults??

That sounds very like the impellor is on the way out.
The impellor is a small rubber vaned wheel that sucks in cooling water to cool the engine. If it's worn it will not be able to cool the engine efficiently at full revs and this could be causing your alarm to sound.
They are not that expensive, the ones for my outdrives are about €60.00 each although fitting can be a little tricky unless you know what you're at.
It is located in the lower leg and you have to separate the gearbox/prop housing from the rest of the leg to access it.
on a side note you should never run an outboard out of the water, at least not for more than a few seconds, as the impellor vanes will be running dry and will soon be damaged.
Mark.

brembo26

Hifive wrote: »

That sounds very like the impellor is on the way out.
If it's worn it will not be able to cool the engine efficiently at full revs and this could be causing your alarm to sound.

Thing is there is very strong pressure coming out of it thouh and the thermostat kicks fine all the time.

The alarm only seems to sound at about 30 or 31 degrees with full throttle in gear. so its not as if its over heating.

Hifive wrote: »

on a side note you should never run an outboard out of the water, at least not for more than a few seconds, as the impellor vanes will be running dry and will soon be damaged.

its ok because it does be hooked up to a water "ear muff" thingy so its not running dry. Tis in the water now anyway:)

JohnCleary

brembo - The alarm was sounding BEFORE the service.

You can't tell if the impellor is shot just by the tell-tale, the tell-tale is only an indicator that there is water pumping, not that there is enough pumping. Majority of water comes out through the hub in the prop.

Engine should NEVER be revved with only 'ear muffs' on, they don't provide enough water. Ear muffs should only be used for starting/flushing the engine out of the water at idle revs.

My opinion of the problem? Faulty temp sensor causing a dodge reading hence alarm sounding (or possibly failsafe). Why? Well, at idle/in gear at low rev's the temp finally comes up to about 80 degrees, you can see the stat opening as temp drops. However, when at WOT on the water, the temp drops to around 30-40 degrees and then the alarm sounds. Now, what engine in the world runs at 30-40 degrees at WOT? NONE! These engines should run at around 82 - 86 degrees at WOT, with a genuine 'overheat' alarm kicking in at around 94-96 degrees.

Anyhow, i'm not on the boat crew so it's none of my business, but in short, engine needs to go on the diagnostics.

brembo26

i didnt post this, himself did on my account. ill show him this later if im down to him.

ty for replies.